Those are pinmoor.The lady invented these because she had peoblems with her hands.They cost 40dollars for 100.
You can buy less but once you buy them you will never have to buy again because they self seal.She said she would never have me as a client because they last for ever.
Her web sight is www.pinmoor.com she has a video on it to explain how they work.You can do a queen quilt with the 100. Depends how many you use in it.They are made from silicone.I bought them and called her.Men are buying them to use on the end of fish hooks for flyfishing so they dont jab their fingers.Im using them and they work great.